Liquid dispensing apparatus



March 2, 1954- LUNDH 2,670,683

LIQUID DISPENSING APPARATUS Filed Oct- 5, 1950 w I: U 12 0') O) div- W m g -0 A SJ' a was INVENTOR HELMER LUNDH ATTORNEYS Patented Mar. 2, 1954 UNITED STATES PATENT OFFICE LIQUID DISPENSING APPARATUS Helmer Lundh, Sjursoya, Oslo, Norway Application October 3, 1950, Serial No. 188,090

3 Claims.

The present invention relates to dispensing apparatus adapted to dispense definite quantities of liquids from a storage tank under the use of a piston pump which by each stroke delivers the desired liquid quantity, and the object of the invention is certain improvements in such apparatus permitting any number of the apparatus to be driven by one and the same driving means, the liquid quantity delivered by each stroke of the pump being at the same time very easily and accurately adjustable.

According to the invention, the piston rod of the pump comprises a tube extending through the pump cylinder, a reciprocating rod being carried within and coupled to the said tube so as to impart a reciprocating movement to the same. The accurate adjustment of the liquid quantity delivered by the pump may be effected by making the connection between the piston rod and the driving rod in such a manner as to impart an adjustable backlash to the reciprocating rod prior to its actuating the piston rod.

According to the invention the coupling means between the said tube and the reciprocating rod may comprise a sleeve or the like adapted to engage both a catch provided on the driving rod and a catch provided on the piston rod, one or both of said catches being axially adjustably secured to the respective rod for the purpose of adjusting the backlash. The pump may be singleacting, but is preferably made double-acting, the pump cylinder being on either side of the piston connected to an inlet and a discharge valve.

For conveying of cans or containers to be charged through the discharge valves of the apparatus according to the present invention any suitable conveyor means may be used which performs an intermittent movement synchronously with the driving rod, so that the cans are at rest during the charging. A conveyor means particularly adapted for the present purpose is disclosed in my co-pending application Serial No. 188,089, entitled Improvement in Can Seaming Machines, filed October 3, 1950.

The invention also relates to an improvement in the discharge valve whereby any waste of liquid by dripping from the valve upon closing of the same is avoided. According to the invention this is achieved by forming the end of the valve body opposite to the end facing the discharge opening as a piston provided with a pressure surface of an area which is greater than that of the discharge opening, this piston being slideably mounted in a corresponding bore in the valve casing in such a manner that the valve body is raised relatively to the said discharge opening by the pressure exerted by the liquid coming from the pump, and by providing the valve body with a bore, one end of which opens into free air and the other end into a closed space on the side of the piston remote from the said pressure surface. Thus, when the piston is raised, the air contained in the space above the piston is compressed and some air is forced out through the bore. When the delivery of the liquid quantity is finished and the liquid pressure on the piston surface consequently decreases, the valve body will, by gravity and preferably assisted by spring action return to closing, position against the discharge opening, thereby creating a reduced pressure in the said closed space above the piston, whereby air is caused to flow in through the said bore in the valve body, thereby carrying along any oil drops possibly accumulated at the lower end of the valve body. In order to secure a complete removal of all liquid drops, the lower, free end of the valve body is made conical and extending slightly beyond the valve seat of the discharge opening, when in closing position, the bore being at the same time so arranged as to open in the center line of the valve body.

In the accompanying, drawing an embodiment of an apparatus according to the invention is illustrated in a vertical sectional view. j

In the embodiment shown, a double-acting pump, is serving the dispensing of the liquid, the pump cylinder to either side of the pistonbeing connected to its individual discharge valve. Such valves are preferably positioned at different distances from the. vertical plane through the center line of the pump, so as to make each of them adapted to serve the charging of cans fed by spaced parallelly running conveyor means, which have such intermittent movement that they are alternatively at rest during the charging of a can through the corresponding discharge valve.

In the drawing, I is the pump cylinder and 2 the piston which is mounted on a tubular piston rod 3 extending through the cylinder. The liquid is fed from a tank which is not shown and may be of any suitable form and position, but should preferably be placed at a higher level than the pump so as to feed the same by gravity through pipes the ends of which are shown at 4 and 5, respectively on either side of the piston. The pipes 4 and 5 are connected to the pump through suction valves 6 and 1, respectively, and the pump is also provided with pressure valves 8 and 9, through which the liquid is conveyed alternatively to the discharge valves HI and I l respectively.

3 The pump is operated by a reciprocating rod l2 which is carried within the tubular piston rod 3 and connected to the same by means of a coupling [3. The rod I2 is reciprocated in any suitable manner, such as by means of a crank disc l4 and connecting rod IS, the disc l4 being continuously rotated by any suitable energy source. The coupling mmomprises a sieeve-iwhicrsatseach end is provided with an mward bent'fiange I26 and I1, respectively. The sleeve, which preferably is made readily removable, embraces a catch [8 provided on the driving rod 12 eandiaacatch l9 provided on the piston rod 3, the said catches l8 and [9 being adapted to engagettheflflanges l6 and I! respectively of the "sleeve. The distances between the catches l8 arfd'f 9 on one"han'd and between the flanges l6 and tlgonsthecother are so dimensioned that the driving rod l2lhas a certain backlash prior to its actuationof .the piston rod 2 in either direction, this backlash .being adjustable by adjusting of the axialgposition of the catch'19,Trelativelyto the "rod3, :the catchIS being "fortliispurposein screw thread engagement with the piston rod.

"The pressure valves Brand 9 ofthe 'pumpiare, throughgpipes 8a, and"9a"fee'ding into "discharge valves and! l, respectively each provide'd with a; valve body 20; the'upperipartof which isiormed 'asapiston' body lpresenting a-pressure "surface 22' of 'an' areanvhich isgreater 'thanthe"area-cf the discharge" opening 2 3- 0f the" valve and which is"slideablyffittedm'the valve casing. Further, the valve body 20 is; provided with a central'ioore 24 "opening into free air *through a conical end portion 2 -ofthe valvebody'and'atthe opposite 'en'dfiopening into thelosd space? 6 above the piston-"body '2 l The 'valvebody 'is ioade'd with a screw-spring 2'1. Thisspringis' in the example Shownaccommodated in the sp'ace f6- -above the pistonbody, but it -maya-lso be arranged in any other "convenient manner.

When-liquid forced from the pump through any of the valves 8 arid 9'-to=thedisc'harge valves t0 "and -i I, respectively "the discharge -valve in question 'is "opened due to the liqi-i-id I pressure against =the sur'iace 22 -'-of th'e ipis'ton body 2 I, thereby leaving free discharge flow through -the opening -23. By the raising of the' valve body 20, the air= containedx in I the wspace 1 l6 eabove the piston is compressed to the'efiect thatapertain quantity of J air is f forced out through :the .:bore 'll. When the pump piston 2 reachesfits :end position, thedelivery or liquid l-to ithe discharge valve isd-iscontinuedwhereby the pressureagainst 2 0 is caused:- to move :to: closingposition by :gravity and by the action of the spring 21. Consequently, a reduced pressure is created in the space 26 above the piston body 2|, whereby air is drawn up through the bore 24, thereby carrying with it any liquid drops which may be accumulated at the free end of the valve body 20.

What I claim is:

A 1.rArliquidxiispensingeapparatns comprising a *piston epump-which byeeach strilaeirielivers the desired liquid quantity to be dispensed, said pump "including a cylinder provided with inlet and -.exhaust waives, a piston reciprocable in said cylinder, and a piston rod, the piston rod of the ipumplibeingcmade in the form of a tubular mem- ,ber having an opening in each end and extending through the pump cylinder, a reciprocating rod exteniiingtthrongh the said tubular member, and

:mup'ling means provided between the said tubular anember and the said rod to transfer the reciprocating movement of the said rod to the said tubularmember and thereby to the piston, said coupling "means being "external of the tubular member.

2.. An apparatus as-claimed in" claim1;wherein the coupling "means between the said tubular piston rod andthesaid'reciprocatin'g driving rdd includes adjustablelost=motion' means comprising catch members onsaidfi pistonrod'an'd catch memberston"said"drivingrod,at leastone ofsaid catch.membersbeingadjustable. axial-1y for "adjustmentofthe liquid-quantity*to' be dispensed.

3. An apparatus as claimed inclaim l; wherein the coupling means between the said tubuiar piston rod and the said *reciprocating rod comprises-a -"'sleeve' member, acatch member *cn the reciprocating "rod and a second catch 'member on the tubular piston red; the said sleeve member being provided with means adapted to *engage the said catch -members; a't least one of the said catch members being axially adjustabl-y mounted for adjustment of the free 1 motion of the *said reciprocating rod.

References P Cited 1 in the file of this cpatent UNITEDSTATES PATENTS 'Nuniber Name Date 437,1'62 "Miller et a1 Sept."23, 1890 "536,356 Montalto Mar. 26, '1895 $327,272 Dllgren .Jan. "6,1920 2',l;45',854 Bijus Feb. "7, 1939 "23911826 "Meyers et' al Dec; 20; I949 :FOREIGN PATENTS Number Country Date 18,638 Netherlands "11 928 

